Cheat Codes 
Highlight the Multiplayer selection in the options menu, 
then hold L1 + R1 + R2 + Right and press X to display the 
cheat menu. Then, enter one of the following codes to activate 
the corresponding cheat function:

5-0 mode 
Enter BDK as a code at the cheat menu.

Sidecar mode 
Enter CMB as a code at the cheat menu.

Jailbreak mode 
Enter KLFSDA as a code at the cheat menu.

Four nitros in Jailbreak mode 
Enter FDMFG as a code at the cheat menu.